Explanation: What
does a
comet nucleus look like?
Formed from the
primordial stuff
of the solar system, it is thought to resemble a very dirty iceberg.
But for active comets,
telescopic images only reveal the surrounding cloud of gas and dust, the
comet's coma, and
the characteristic cometary tails.
In 1986, the
European spacecraft Giottoencountered the nucleus of
Halley's comet as it approached the sun.
Data from Giotto's camera was used to generate
this enhanced image of the potato shaped nucleus which
measures roughly 15 kilometers across.
It shows surface features on the dark nucleus
against the bright background of the coma as the icy
material is vaporized by the Sun's heat.
Every 76 years
Comet
Halley returns to the inner solar system
and each time the nucleus sheds about a 6 meter deep layer of its
ice and rock into space.
This debris composes Halley's tails
and leaves an orbiting trail
responsible for the Orionidsmeteor shower.